1. Mail Shield does not filter outgoing emails. (Eddy, there’s no checkmark for that on Avast! for Mac, there is no such function in the Mac version)
  2. Why do you say your email is sending out spam? Because people are receiving spam messages with your email address on them? You should know that it’s very easy to spoof the ‘from:’ field of an email, so it doesn’t actually mean they are coming from your computer.
  3. If your computer is actually being turned into a spam bot, that means there’s a piece of software running that is doing that job, Mail shield does not deal with that, however, a full system scan might detect the malicious software.